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原文传递 Evaluation of the Maturity Method to Estimate Concrete Strength in Field Applications.

题名：	Evaluation of the Maturity Method to Estimate Concrete Strength in Field Applications.
作者：	nixon, j. m. schindler, a. k. barnes, r. w. wade, s. a.
关键词：	construction, girders, bridge decks, temperature measuring instruments, laboratory tests, alabama, implementation, evaluation
摘要：	Estimating the strength of concrete is essential to contractors and engineers to allow concrete construction operations to proceed safely and expediently. The maturity method is a technique that allows the in-place concrete strength to be estimated using the time and temperature history of freshly placed concrete. The purpose of this project was to evaluate the accuracy of the maturity method to assess concrete strength under field conditions and develop a specification for Alabama Department of Transportation (ALDOT) to implement the maturity method. The construction of a precast prestressed girder and bridge deck sections were monitored for this project. For each project, the accuracy of the maturity method for estimating the in-place strength of concrete was evaluated. A mock girder and mock bridge decks were constructed to test the in-place strength. The in-place strength was tested with pullout tests, compression testing of cast-in-place cylinders, and compression testing of cores. The accuracy of using laboratory-cured specimens versus field-cured specimens for developing the strength-maturity relationship to estimate the in-place strength was also evaluated. Seasonal effects on the maturity method were also evaluated during the bridge deck project. The optimum locations of temperature sensors used in estimating the in-place strength were determined in the prestressed girder and bridge deck. Finally, the American Society of Testing and Materials (ASTM) Standard ASTM C 1074 recommended procedures for implementing the maturity method were evaluated on the actual bridge decks that were constructed. / NOTE: Research rept. / Supplementary Notes: Sponsored by Alabama Dept. of Transportation, Montgomery. and Federal Highway Administration, Montgomery, AL. Alabama Div. / Availability Note: Order this product from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5285 Port Royal Road, Springfield, VA, 22161, USA.
总页数：	u0817；332p
报告类型：	科技报告